1. Field Of The Invention
The present invention relates generally to hand-operated cutting tools, and more specifically to such tools adapted to cutting a circle in a planar workpiece.
2. Description Of The Related Art
Craftspersons of many types frequently need to cut neat, circular holes in planar sheet material. Various well known tools are available for this purpose. For example, a hole saw affixed to a power drill works well, and if one uses great care a fairly neat circle may be cut with a sabre saw. However, as often occurs on remote building sites, electrical power is not available. Power tools with rechargeable battery packs offer one option, but these are heavy and even a single tool takes up considerable space in a toolbox. In addition, even though a drill-powered hole saw cuts holes with, perhaps, the greatest precision, a drill of sufficient power to cut larger holes is likely to be unwieldy.
Fewer options are found among the hand tools. A keyhole saw is difficult to use, and imprecise in any case. A chisel is so much more crude that it generally goes unconsidered.
As is often the case on a job site, the circular hole to be cut is on a vertical or other non-horizontal surface. This tends to reduce the precision available from all the above tools but the drill-powered hole saw, the hole saw's limitations already having been discussed.
Thus, a need exists for a compact, lightweight hand tool for cutting circles in such planar sheet material as fiberglass, fiberboard, wood and thin metal.